Okafor for the #3 seems like a pretty fair deal. If the deal needs to be 'evened out' one way or the other, that should be easy enough with both teams' assets. We have #24, #26, Covington, Grant, Richaun Holmes, Stauskas. They have 3 1st round picks, 5 2nd rounders, and a few spare pieces (Jerebko, Hunter, Zeller, Rozier).
It would be a risk if Okafor dramatically improves or if the #3 pick is a bust, but Noel, Embiid, Saric and Simmons is a good core of young bigs (Holmes, Grant and Covington have potential too), while our backcourt is bereft of talent. One of picks 24 & 26 and next year's picks could always be used on a big man as well.
A core of Noel, Embiid, Simmons, Saric and Dunn might just need 1-2 good shooters/defenders to be a really nice team in a couple of years.